1. Clouds and Radiation

3. “..there are substantial uncertainties in decadal trends in all data sets and at present there is no clear consensus on changes in total cloudiness over decadal time scales.” IPCC-The Scientific Basis-Chapter 3, p. 277 An increase in both clouds and precipitation has occurred over many parts of the land surface (Dai et al., 1999, 2004a, 2006), although not in the tropics and subtropics (which dominate the global land mean; Section 3.3.2.2). IPCC-The Scientific Basis-Chapter 3, p. 279

4. IPCC WG1 AR4 Report Variability caused by model representations of clouds

5. How do Clouds Alter the State of the Atmospheric Column? Diabatic Heating Profiles –Latent Heating –Net column latent heating = Precipitation mass * L, where L = latent heat –Radiative Heating –Net column radiative heating= net incoming minus net outgoing –Profiles of diabatic heating impact atmospheric dynamic and thermodynamic structure

6. Radiative Heating and Cooling of the atmospheric column

7. SHORTWAVE λ=1-4 μm includes visible band a cloud-free column

8. LONGWAVE λ > 4 μm

9. Radiative Flux Divergence Primer Radiative Flux Divergence = net radiation into column - net radiation out of column positive values imply heating negative values imply cooling negpos NET

10. SHORTWAVE

11. cirrus (ice clouds) thin wispy semi-transparent o optically thin

12. SHORTWAVE cumulus convection and other optically thick clouds (liquid/mixed/ice) base near surface > 30% coverage vertical development layer clouds

13. Cirrus and Cumulus from the Space Shuttle Courtesy NASA CERES

14. LONGWAVE

15. cumulus convection and other optically thick clouds (liquid/mixed/ice)

16. LONGWAVE

17. What Cloud Properties Change the Radiative Heating Rate Profile? 1.Hemispheric cloud coverage cloud 2.Optical thickness of individual clouds and layers 3.Height in the atmosphere 4.Layer coherence (or overlap) 5.Composition Contain ice crystals, liquid water, or both? Particle sizes? Particle concentrations?

18. How Does the Location of Cloud Impact the Surface Temperature? Low Clouds ~ 2-km High Clouds ~10-km COOLINGWARMING

20. What types of remote sensors do we use to make cloud measurements? Vertically-Pointing Lasers (LIDARs) –measure the height of the lowest cloud base –below cloud concentrations of aerosol and water vapor –beam quickly disperses inside cloud Cloud Radars –cloud location and microphysical composition –in-cloud updrafts, downdrafts, and turbulence Microwave Radiometers –measure the total amount of liquid water in atmosphere –can’t determine location of liquid –no measure of ice water content

21. Negligible Return Cloud and Aerosol ParticlesCloud droplets Surface 10-km 20-km 24 Hours Lidar Data from Southern Great Plains Ice Clouds Low Clouds No Signal 7:00 pm7:00 am7:00 pm time

22. Niamey, Niger, Africa 0000 Negligible Return Cloud Droplets Cloud and/or Aerosol 0000 1200 0 5 10 15 20 Time (UTC) Height (km) Biomass Burning Dust LIQUID CLOUDS

23. VHF UHF 10 cm 8 mm 3.2 mm cloud radars

24. 3.2 mm 95 GHz 8.0 mm 35 GHz Maximum Propagation Distance 20-30 km10-15 km Cloud Radar Wavelengths

25. The DOE ARM Cloud Radars

26. Small Cloud ParticlesTypical Cloud ParticlesVery Light Precipitation Surface 10-km 20-km Cloud Radar Data from Southern Great Plains Black Dots: Laser Measurements Of Cloud Base Height 7:00 pm7:00 am7:00 pm time

27. Evolution of Cloud Radar Science Cloud Structure and Processes Cloud Statistics Cloud Composition diurnal variation in cloud fractional coverage and surface precipitation for June 2006 over Lamont, Oklahoma (Courtesy: Lynne DiPretore)

28. Height (km) Cloud Fraction (%) GFS cloud initialization data mandatory radiosonde data satellite retrievals of temperature satellite-derived cloud motion vector aircraft cloud fraction parameterization: Xu and Randall (1996) August GFS 10-15 km cloud fraction larger than AMF AMF 0-10 km cloud fraction larger than GFS Kollias, P, M.A. Miller, K.Johnson, M. Jensen, D. Troyan, 2008

29. Surface 2-km 10-km Laser Radar Base Radar Echo Top Base Top Low Radar Sensitivity Radar Echo Radar Echo Microwave Radiometer Emission Multiple remote sensors required to measure non- and weakly precipitating clouds

31. 7:00 pm7:00 am7:00 pm 1410 17 25 Liquid Cloud Particle Median Radius Micrometers Height (km) 2 4 6 0 time Miller and Johnson, 2003

32. Tobin et al., 2007

33. Clouds and Radiation from Space (and high altitude)

34. 0 2 4 6 altitude (km) 19:30 19:53 June 12, 2006 Oklahoma CPL backscatter profiles and MAS comparison distance (km) 0 275 0 +37 -37 km time (UTC) Matt McGill/NASA Goddard

35. A-TRAIN CONSTELLATION The Afternoon or "A-Train" satellite constellation presently consists of 5 satellites Two additional satellites, OCO and Glory, were supposed to join the constellation OCO was lost during a launch failure on 2/24/2009. Glory is scheduled to launch (02/23/11) Approx equator crossing times

36. 36 Afternoon Constellation Coincidental Observations (Source: M. Schoeberl) MODIS/ CERES IR Properties of Clouds AIRS Temperature and H 2 O Sounding Aqua CloudSat PARASOL CALIPSO- Aerosol and cloud heights Cloudsat - cloud droplets PARASOL - aerosol and cloud polarization Glory-aerosol size and chemistry CALIPSO OCO-2? Aura OMI - Cloud heights OMI & HIRLDS – Aerosols MLS& TES - H 2 O & temp profiles MLS & HIRDLS – Cirrus clouds Glory

37. CloudSat (Hurricane Ike) 37

38. CloudSat 38

39. Radar/Lidar Combined Product Development Formation flying is a key design element in cloudsat CloudSat has demonstrated formation flying as a practical observing strategy for EO. Overlap of the CloudSat footprint and the CALIPSO footprint, within 15 seconds, is achieved >90% of the time.

40. Microwave Limb Sounder ECMWFCloudSat A-Train Cloud Ice

42. Visual Images of the Sky cloud coverage (versus cloud fraction) simple! digitize images and … daytime only integrated quantity

43. Lidar/Radar combined ice microphysics - new A-Train ice cloud microphysics Zhien Wang University of Wyoming